Cilastatin inhibits the human enzyme dehydropeptidase.

[1] Dehydropeptidase is an enzyme found in the kidney and is responsible for degrading the antibiotic imipenem.

Cilastatin can therefore be combined intravenously with imipenem in order to protect it from degradation, prolonging its antibacterial effect.

This property is due to the physicochemical similarities between membrane dipeptidase (MDP), the compound it is usually set to target, and the bacterial metallo-beta-lactamase carried by the CphA gene.

[1] The combination allows the antibiotic to be more effective by changing the pharmacokinetics involved.